Huge beast.
AC 12 HP60 (8d12 + 8)
Speed. 30 ft. Swim 30 ft
STR +4
DEX +2
CON +1
INT -5
WIS+0
CHA -4
Skills. Perception +2
Senses. Blindsight 10 ft. passive Perception 12
Languages.-
Actions
Bite. +6, 10 ft. 11 (2d6+4) piercing damage.
Constrict. +6 to hit. 5 ft. 13 (2d8 +4) Bludgeoning damage. And the target is grappled (escape DC 16). Until this grapple ends, the creature is restrained, and the snake can not constrict another target.
Medium beast.
AC 11 (natural armor) HP19 (3d8 + 6)
Speed. 40 ft. Climb 30 ft
STR +2
DEX +0
CON +2
INT -4
WIS+1
CHA -2
Skills. Perception +3
Senses. passive Perception 13
Languages.-
Actions
Bite. +6, 10 ft. 11 (2d6+4) piercing damage.
Constrict. +6 to hit. 5 ft. 13 (2d8 +4) Bludgeoning damage.